The technique of creating a gene library by inserting DNA fragments into plasmid vectors and introducing into bacteria is: MCQ with Answer and Explanation

Explanation:
A balanced diet provides all the essential nutrients (carbohydrates, proteins, fats, vitamins, minerals, and water) in the correct proportions required for optimal health and growth. Malnutrition refers to deficiencies, excesses, or imbalances in a person's intake of energy and/or nutrients; therefore, overeating (leading to obesity) is a form of malnutrition. Water is an essential nutrient, crucial for hydration, transport, and chemical reactions, though it provides no calories. Thus, statements 1 and 2 are correct.

Explanation:
Immunoglobulin A (IgA) is the primary antibody found in mucosal secretions, including saliva, tears, nasal secretions, breast milk (colostrum), and the respiratory and gastrointestinal tracts. It plays a crucial role in mucosal immunity by preventing the attachment of pathogens to epithelial cells, a process known as immune exclusion. IgG is the most abundant in blood, IgM is the first to be produced in an infection, and IgE is involved in allergies.

Explanation:
Stanley Miller and Harold Urey simulated early Earth conditions and obtained amino acids (like glycine and alanine) by applying electric discharge to a mixture of gases.